Physiologic jaundiceBilirubin is the final product of heme degradation. At physiologic pH, bilirubin is insoluble in plasma and requires protein binding with albumin. After conjugation in the liver by glucuronyl transferase, it is excreted in bile. Hyperbilirubinemia develops due to increased hematocrit, decreased RBC lifespan, increased enterohepatic circulation and immature glucuronyl transferase (slow conjugation).

Term infants: onset 2-3days, resolution by 7days

Premature: higher peak and longer duration

Breastfeeding and Jaundice

Breastfeeding jaundice (common)

Early-onset exaggerated physiologic jaundice

Relative caloric deprivation in the first few days of life due to lack of milk production